My PhD project was on biogeochemical cycling in the southern South China Sea with a focus on Malaysian territorial waters along the east coast Peninsular Malaysia and Brunei Bay (Figure 1). This work formed part of the Higher Institute Center of Excellence (HiCoe) research programme phase 1 (http://inos.umt.edu.my/?page_id=8357&lang=en). During this project, my research investigated the annual nutrient cycling, established the current levels and distributions of nutrients in these marine waters, and also evaluated the potential threats from human activity to this region. My research therefore involved the measurement of in situ physical parameters and nutrients, assessment of the size fractionation of the dissolved organic nutrients, measurement of nitrogen uptake rates by phytoplankton through the use of stable isotopes as well as investigation of water-sediment nutrient exchange (Figure 2). Ultimately, my research has improved the understanding of the physical and biogeochemical processes controlling primary production in the southern South China Sea. In addition, these findings in Brunei Bay also provides an evidence base for the Legislative, Administrative and Policy (LAP) team that advises the Malaysian Government in establishing the Brunei Bay as an internationally designated Marine Protected Area.